Used to create calligraphic rulings for western calligraphy::

Usage: ruling.py [options] output_file
    
    Options:
      -h, --help            show this help message and exit
      -n NIB_WIDTH, --nib-width=NIB_WIDTH
                            Width of the nib specified in millimeters. All other
                            measurements are multiples of this.
      -p PARTITIONS, --partitions=PARTITIONS
                            Comma separated list of partitions in each line
                            (specified in nib widths)
      -g GAP, --gap=GAP     gap between lines (specified in nib widths)
      --top-margin=TOP_MARGIN
                            Top margin (specified in nib widths). Default is 2
      -r RULINGS, --rulings=RULINGS
                            How many rulings to draw. Default is 10
      -a ANGLES, --angle=ANGLES
                            Comma separated list of angles (in degrees) for which
                            to draw lines on the page (for pen angle, serifs etc.)
      -t TITLE, --title=TITLE
                            A title for this ruling (usually the font name)

